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 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /**
  * @file
  *
  * @ingroup RTEMSScoreSysLockMutex
  *
  * @brief This source file contains the implementation of
  *   _Mutex_Acquire(), _Mutex_Acquire_timed(), _Mutex_Acquire_timed_ticks(),
  *   _Mutex_Try_acquire(), _Mutex_Release(), _Mutex_recursive_Acquire(),
  *   _Mutex_recursive_Acquire_timed(), _Mutex_recursive_Try_acquire(), and
  *   _Mutex_recursive_Release().
  */
 
 /*
  * Copyright (C) 2015, 2016 embedded brains GmbH & Co. KG
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
 #include <sys/lock.h>
 #include <errno.h>
 
 #include <rtems/score/assert.h>
 #include <rtems/score/muteximpl.h>
 #include <rtems/score/threadimpl.h>
 #include <rtems/score/todimpl.h>
 
 /**
  * @defgroup RTEMSScoreSysLockMutex System Lock Mutex Handler
  *
  * @ingroup RTEMSScore
  *
  * @brief This group contains the System Lock Mutex Handler implementation.
  *
  * The interfaces are defined by Newlib in <sys/lock.h>.  The system lock
  * mutexes are used for Newlib internal locking, the C++ standard library
  * provided by GCC, the OpenMP support provided by GCC, the self-contained
  * objects API provided by RTEMS, and the SuperCore internal mutexes such as
  * the objects allocator lock (see ::API_Mutex_Control).
  */
 
 #define MUTEX_TQ_OPERATIONS &_Thread_queue_Operations_priority_inherit
 
 RTEMS_STATIC_ASSERT(
   offsetof( Mutex_Control, Queue )
     == offsetof( struct _Mutex_Control, _Queue ),
   MUTEX_CONTROL_QUEUE
 );
 
 RTEMS_STATIC_ASSERT(
   sizeof( Mutex_Control ) == sizeof( struct _Mutex_Control ),
   MUTEX_CONTROL_SIZE
 );
 
 RTEMS_STATIC_ASSERT(
   offsetof( Mutex_recursive_Control, Mutex )
     == offsetof( struct _Mutex_recursive_Control, _Mutex ),
   MUTEX_RECURSIVE_CONTROL_MUTEX
 );
 
 RTEMS_STATIC_ASSERT(
   offsetof( Mutex_recursive_Control, nest_level )
     == offsetof( struct _Mutex_recursive_Control, _nest_level ),
   MUTEX_RECURSIVE_CONTROL_NEST_LEVEL
 );
 
 RTEMS_STATIC_ASSERT(
   sizeof( Mutex_recursive_Control )
     == sizeof( struct _Mutex_recursive_Control ),
   MUTEX_RECURSIVE_CONTROL_SIZE
 );
 
 static Mutex_Control *_Mutex_Get( struct _Mutex_Control *_mutex )
 {
   return (Mutex_Control *) _mutex;
 }
 
 static Thread_Control *_Mutex_Queue_acquire_critical(
   Mutex_Control        *mutex,
   Thread_queue_Context *queue_context
 )
 {
   Thread_Control *executing;
 
   executing = _Thread_Executing;
   _Thread_queue_Queue_acquire_critical(
     &mutex->Queue.Queue,
     &executing->Potpourri_stats,
     &queue_context->Lock_context.Lock_context
   );
 
   return executing;
 }
 
 static void _Mutex_Queue_release(
   Mutex_Control        *mutex,
   ISR_Level             level,
   Thread_queue_Context *queue_context
 )
 {
   _Thread_queue_Queue_release_critical(
     &mutex->Queue.Queue,
     &queue_context->Lock_context.Lock_context
   );
   _ISR_Local_enable( level );
 }
 
 static void _Mutex_Acquire_slow(
   Mutex_Control        *mutex,
   Thread_Control       *owner,
   Thread_Control       *executing,
   ISR_Level             level,
   Thread_queue_Context *queue_context
 )
 {
   _Thread_queue_Context_set_thread_state(
     queue_context,
     STATES_WAITING_FOR_MUTEX
   );
   _Thread_queue_Context_set_deadlock_callout(
     queue_context,
     _Thread_queue_Deadlock_fatal
   );
   _Thread_queue_Context_set_ISR_level( queue_context, level );
   _Thread_queue_Enqueue(
     &mutex->Queue.Queue,
     MUTEX_TQ_OPERATIONS,
     executing,
     queue_context
   );
 }
 
 static void _Mutex_Release_critical(
   Mutex_Control        *mutex,
   Thread_Control       *executing,
   ISR_Level             level,
   Thread_queue_Context *queue_context
 )
 {
   Thread_queue_Heads *heads;
 
   heads = mutex->Queue.Queue.heads;
   mutex->Queue.Queue.owner = NULL;
   _Thread_Resource_count_decrement( executing );
 
   if ( RTEMS_PREDICT_TRUE( heads == NULL ) ) {
     _Mutex_Queue_release( mutex, level, queue_context );
   } else {
     _Thread_queue_Context_set_ISR_level( queue_context, level );
     _Thread_queue_Surrender(
       &mutex->Queue.Queue,
       heads,
       executing,
       queue_context,
       MUTEX_TQ_OPERATIONS
     );
   }
 }
 
 void _Mutex_Acquire( struct _Mutex_Control *_mutex )
 {
   Mutex_Control        *mutex;
   Thread_queue_Context  queue_context;
   ISR_Level             level;
   Thread_Control       *executing;
   Thread_Control       *owner;
 
   mutex = _Mutex_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( mutex, &queue_context );
 
   owner = mutex->Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     _Mutex_Queue_release( mutex, level, &queue_context );
   } else {
     _Thread_queue_Context_set_enqueue_do_nothing_extra( &queue_context );
     _Mutex_Acquire_slow( mutex, owner, executing, level, &queue_context );
   }
 }
 
 int _Mutex_Acquire_timed(
   struct _Mutex_Control *_mutex,
   const struct timespec *abstime
 )
 {
   Mutex_Control        *mutex;
   Thread_queue_Context  queue_context;
   ISR_Level             level;
   Thread_Control       *executing;
   Thread_Control       *owner;
 
   mutex = _Mutex_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( mutex, &queue_context );
 
   owner = mutex->Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     _Mutex_Queue_release( mutex, level, &queue_context );
 
     return 0;
   } else {
     _Thread_queue_Context_set_enqueue_timeout_realtime_timespec(
       &queue_context,
       abstime,
       true
     );
     _Mutex_Acquire_slow( mutex, owner, executing, level, &queue_context );
 
     return STATUS_GET_POSIX( _Thread_Wait_get_status( executing ) );
   }
 }
 
 int _Mutex_Try_acquire( struct _Mutex_Control *_mutex )
 {
   Mutex_Control        *mutex;
   Thread_queue_Context  queue_context;
   ISR_Level             level;
   Thread_Control       *executing;
   Thread_Control       *owner;
   int                   eno;
 
   mutex = _Mutex_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( mutex, &queue_context );
 
   owner = mutex->Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     eno = 0;
   } else {
     eno = EBUSY;
   }
 
   _Mutex_Queue_release( mutex, level, &queue_context );
 
   return eno;
 }
 
 void _Mutex_Release( struct _Mutex_Control *_mutex )
 {
   Mutex_Control        *mutex;
   Thread_queue_Context  queue_context;
   ISR_Level             level;
   Thread_Control       *executing;
 
   mutex = _Mutex_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( mutex, &queue_context );
 
   _Assert( mutex->Queue.Queue.owner == executing );
 
   _Mutex_Release_critical( mutex, executing, level, &queue_context );
 }
 
 static Mutex_recursive_Control *_Mutex_recursive_Get(
   struct _Mutex_recursive_Control *_mutex
 )
 {
   return (Mutex_recursive_Control *) _mutex;
 }
 
 void _Mutex_recursive_Acquire( struct _Mutex_recursive_Control *_mutex )
 {
   Mutex_recursive_Control *mutex;
   Thread_queue_Context     queue_context;
   ISR_Level             level;
   Thread_Control          *executing;
   Thread_Control          *owner;
 
   mutex = _Mutex_recursive_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( &mutex->Mutex, &queue_context );
 
   owner = mutex->Mutex.Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Mutex.Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
   } else if ( owner == executing ) {
     ++mutex->nest_level;
     _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
   } else {
     _Thread_queue_Context_set_enqueue_do_nothing_extra( &queue_context );
     _Mutex_Acquire_slow( &mutex->Mutex, owner, executing, level, &queue_context );
   }
 }
 
 int _Mutex_recursive_Acquire_timed(
   struct _Mutex_recursive_Control *_mutex,
   const struct timespec           *abstime
 )
 {
   Mutex_recursive_Control *mutex;
   Thread_queue_Context     queue_context;
   ISR_Level                level;
   Thread_Control          *executing;
   Thread_Control          *owner;
 
   mutex = _Mutex_recursive_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( &mutex->Mutex, &queue_context );
 
   owner = mutex->Mutex.Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Mutex.Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
 
     return 0;
   } else if ( owner == executing ) {
     ++mutex->nest_level;
     _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
 
     return 0;
   } else {
     _Thread_queue_Context_set_enqueue_timeout_realtime_timespec(
       &queue_context,
       abstime,
       true
     );
     _Mutex_Acquire_slow( &mutex->Mutex, owner, executing, level, &queue_context );
 
     return STATUS_GET_POSIX( _Thread_Wait_get_status( executing ) );
   }
 }
 
 int _Mutex_recursive_Try_acquire( struct _Mutex_recursive_Control *_mutex )
 {
   Mutex_recursive_Control *mutex;
   Thread_queue_Context     queue_context;
   ISR_Level                level;
   Thread_Control          *executing;
   Thread_Control          *owner;
   int                      eno;
 
   mutex = _Mutex_recursive_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( &mutex->Mutex, &queue_context );
 
   owner = mutex->Mutex.Queue.Queue.owner;
 
   if ( RTEMS_PREDICT_TRUE( owner == NULL ) ) {
     mutex->Mutex.Queue.Queue.owner = executing;
     _Thread_Resource_count_increment( executing );
     eno = 0;
   } else if ( owner == executing ) {
     ++mutex->nest_level;
     eno = 0;
   } else {
     eno = EBUSY;
   }
 
   _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
 
   return eno;
 }
 
 void _Mutex_recursive_Release( struct _Mutex_recursive_Control *_mutex )
 {
   Mutex_recursive_Control *mutex;
   Thread_queue_Context     queue_context;
   ISR_Level                level;
   Thread_Control          *executing;
   unsigned int             nest_level;
 
   mutex = _Mutex_recursive_Get( _mutex );
   _Thread_queue_Context_initialize( &queue_context );
   _Thread_queue_Context_ISR_disable( &queue_context, level );
   executing = _Mutex_Queue_acquire_critical( &mutex->Mutex, &queue_context );
 
   _Assert( mutex->Mutex.Queue.Queue.owner == executing );
 
   nest_level = mutex->nest_level;
 
   if ( RTEMS_PREDICT_TRUE( nest_level == 0 ) ) {
     _Mutex_Release_critical( &mutex->Mutex, executing, level, &queue_context );
   } else {
     mutex->nest_level = nest_level - 1;
 
     _Mutex_Queue_release( &mutex->Mutex, level, &queue_context );
   }
 }

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